Electrolytic apparatus



Oct. 23, 1934. R, A. WILKINS ELECTROLYTIC APPARATUS Filed June 14, 1930 45heets-Sheet 1 m: H w RN Q m:

Inventor;

Oct. 23, 1934. R. A. WILKINS ELECTROLYTIC APPARATUS Filed June 14, 1950 4 Sheets-Sheet 2 MK km mm mm 6 mm hbx Inveuiov: Richardd Oct. 23, 1934. R, A. WILKINS ELECTROLYTIC APPARATUS Filed June 14 1950 4 Sheets-Sheet 3 Oct. 23, 1934.

R, A. WILKINS ELECTROLYTIC APPARATUS .4 Sheets-Sheet 4 Filed June 14, 1950 0% j 5 FEJKIIS Inveido'ir' Richardfl.Wilim, 6957M 7 days.

Patented Oct. 23, 1934 UNITED STATES PATENT OFFICE ELECTROLYTIC APPARATUS Richard A. Wilkins, Beverly, Mass., assignor to Industrial Development Corporation, Boston. Mass., a corporation of Maine Application June 14, 1930, Serial No. 461,091

30 Claims.

My invention relates to electrolytic apparatus, particularly, though not exclusively, for electrodepositing metal upon rotating cylindrical cathodes, as for example, plating relatively thick layers of copper on cylindrical iron print rolls.

The invention will be best understood from the following description when read in the light of the accompanying drawings of one embodiment of the invention selected for illustrative 1O purposes, while the scope of the invention will be more particularly pointed out in the appended claims.

Figure 1 is a vertical longitudinal section, with parts broken away, of plating apparatus constructed according to'the invention;

Fig. 2 is a plan on a smaller scale of the plating apparatus shown by Fig. 1;

Figs. 3, 4, 5 and 6 are, respectively, sections on the lines 3-3, 4-4, 55 and 66 of Fig. 1;

Figs. 7 and 8 are, respectively, transverse vertical sections of the apparatus according to Fig. 1, with fillers inserted for adapting the apparatus for electro-depositing upon smaller drums than'those shown in connection with Fig. 1; and

Fig. 9 is a section on the line 9-9 of Fig. 7.

Referring to the drawings, the embodiment of the invention illustrated comprises a trough 1, the interior of which is approximately semicircular in cross-section so as to provide a surface uniformly spaced from the exterior surfaces of the cylindrical cathodes 3 to be 'plated.

As shown, the trough 1 comprises a shell 5 preferably of relatively thin boiler plate lined with a relatively thin sheet of material insoluble in the electrolyte, this latter material preferably being lead, which metal is insoluble in dilute sulphuric acid, and chemically inert with respect to sulphates of 'copper, zinc, nickel and the like, acid solutions of which are commonly employed 40 as electrolytes. As an example of the construction, but without limitation thereto, the boiler plate and sheet lead each maybe about one-eighth of an inch thick.

Herein, for supporting and reinforcing the shell 5 of which the trough is formed, standards 9 are provided, the latter comprising relatively wide arcuate portions 11 conforming to the outer surface of the shell and being integrally formed with legs 13 having supporting feet 15. As shown, the upper edge portions of the shell are provided with horizontal flanges 1'7 riveted at 19 to the upper horizontal portions 21 of the standards. Herein, the standards at their upper portions are provided with horizontal brackets 23 upon which rest the lower flanges of the channel beams 25,

the latter extending the entire length of the trough and being bolted to the several standards as indicated at 27.

With the present apparatus, electrolyte may be pumped into the trough through the pipe 29,

which latter communicates with the trough at one end thereof close to its bottom. As illustrated, spaced from this end of the trough is a dam consisting of an inclined plate 31, preferably a .sheet of lead, which provides a downwardly inclined breast 33 so that the electrolyte delivered to the trough by the pipe 29 will flow over the top of the dam and be directed down the breast 33 with considerable velocity. As shown, a vertical plate 35 which also preferably is of lead, and which has an angle portion 37 at its lower end directed toward the dam 31, acts as a splash plate to throw electrolyte which splashes thereagainst back into the electrolyte flowing down the breast of the dam, while the angle portion 37, which preferably contacts the electrolyte, acts to secure a smooth-flowing stream thereof at the lower portion of the dam. Inwardly of the trough from the splash plate 35 is shown a dam 39, likewise preferably formed .of a sheet of lead, which for the major portion of its periphery is slightly spaced from the inner surface of the trough as indicated at 41. For supporting the plate 39, conveniently it may be formed with tabs 43 which contact with the lead lining 7 and are secured thereto by "burning. It will be observed that the spaces between the tabs 43 collectively form substantially an arcuate orifice close to the inner surface of the trough, which orifice acts to distribute the electrolyte into the body of the trough close to the inner surface thereof.

The electrolyte may be discharged from the trough at its righthand end, as viewed in Fig. 1, through an arcuate opening 45 in the shellwhich constitutes the trough,'the electrolyte falling from this orifice into a boot 47'when'ce the electrolyte is pumped through a body of-electrolyte replenishing material and is returned to the trough by the way of the pipe 29. The replenishment may be controlled in any convenient way, as for example, in accordance with the method disclosed in United States patent to Merritt No. 1,601,690, dated September 28, 1926.

Herein the electrolyte flows through the trough 1 past the cathode drums or rolls 3 in a relatively swift stream, said drums conveniently being rotated at a velocity which is just below that which will cause splashing of the electrolyte from the trough, although it is quite possible to increase the v locity to above this by use of suitable hoods or the like to prevent splashing. It will be observed that the electrolyte flowing past the drums in Fig. l is distributed in a relatively thin sheet, the thickness of which is equal tothe distance at which the outer surfaces of the drums are spaced from the inner surface of the trough. Spaced inwardly of the trough from the arcuate electrolyte discharge orifice 45 is shown a dam 49 constructed similarly to the dam 39 so as to provide substantially an arcuate orifice 51 extending around the bottom of the trough close to its inner surface. The two orifices 41 and 51 it has been found act to distribute and maintain a swift flow of electrolyte past the drum 3 without material ebullition.

Preferably the flow of electrolyte is such as to 'maintain an electrolyte level indicated at 53 in Fig. 1, such level being very slightly above the upper edge 55 of the dam 49 so that a small portion of the electrolyte will flow over said dam. This acts to maintain the upper surface 53 of the electrolyte substantially horizontal, thus avoiding having portions of the drums nearest the dam 39 submerged a greater distance in the electrolyte than those portions which are nearest the dam 49.

Herein for supporting the drums 3, the shafts 57 of the latter are rotatively mounted in the bearings 59 which, as shown, are secured to the under sides of channel beams 61, the latter being carried at opposite ends upon insulating blocks 63 resting upon the upper flanges of the channel beams 25. Conveniently, the channel beam 61 nearest the dam 39 is permanently secured to the channel beams 25 by volts 65, while the remaining channel beams 61 are removably secured to the channel beams 25 and may be adjusted longitudinally of the latter for accommodating the apparatus to different lengths of drums 3. As shown (Fig. 5), these remaining channel beams 61 are adapted to be secured to the channel beams 25 by C-clamps 67 provided with insulating blocks 69 for preventing the clamp placing the channel beams 61 in electrical communication with the channel beams 25.

For driving the drums, the shafts thereof are shown as secured to each other by a coupling '71, while at the righthand end of the shaft of the righthand drum, as viewed in Fig. 1, is removably secured a pulley '73 driven by a belt 75, which latter passes around a pulley 7'7. As shown, the pulley '77 is mounted on a lay-shaft '79'provided with a pulley 81 which is adapted to be driven from any suitable source of power. Herein the lay-shaft 79 is supported in bearings 83 carried by a standard 85. As shown, the standard 85 has a foot 8'7 adapted to rest upon the upper flange of one of the channel beams 25 and is adapted to be secured to said beam in different positions longitudinally thereof by a clamping device 89.

Herein, the lead lining of the trough constitutes an insoluble anode, and, for placing said lining in electrical communication with the positive terminal of a suitable source of electromotive force, one of the flanges 17 of the trough is provided with a bus bar 91 extending substantially the length of the trough, said bar herein comprising a plurality of copper or like bars 93 secured together in spaced relation and to the said flange 1'7 by cooperating bolts 95 and spacers 9'7. As

shown, cables 99 are attached to said bus bar at convenient points for conducting the current.

For connecting the drums to a negative source of electromotive force, collector rings 101 may be detachably secured to the shaftsat opposite ends of the several drums. Herein, about these collector rings are passed straps 103 which may be formed of thin laminations of sheet copper, the ends of said straps being brought together and soldered as indicated at 105 in Fig. 6. As shown, the channel beams 61 have secured thereto blocks of insulating material 107, to which are secured by means of bolts 109 angle brackets 111, the vertical legs 113 of which latter (as shown by Fig. 6) being spaced from each other. Secured to these spaced legs are pairs of horizontal bars 115, the ends of which carry spaced angle brackets 117, and between the lower legs 119 of these brackets are secured the ends 105 of the straps 103. Conveniently, the portions 119 of the angle brackets may be clamped to the end portions 105 of the straps by bolts 121, which latter pass through perforations in said end portions 105 and through slots 123 in the angle brackets, the slots permitting the straps to be drawn tight against the collector rings.

It will be understood that a plant using print rolls will employ various sizes of the same, these sizes varying in rolls from one to six or more feet in diameter and from four to ten or more feet in length. Conveniently the trough of the apparatus will be of such dimensions as to accommodate the largest size of print roll. For plating smaller sizes of print rolls, fillers may be provided as illustrated in Figs. 7 and 8, these fillers conveniently being of slightly greater length than the drums to be plated and being positioned in the trough with sufficient clearance from the dams 39 and 49 as not to obstruct the flow of electrolyte, which latter, when the fillers are employed, will rise to the upper surfaces of the fillers and flow through the troughs provided therein as about to be described.

Fig. 7 shows a filler 125 provided at its upper side with a pair of troughs 127 for accommodating the print rolls 129, these troughs being of the same or different radii depending on the radii of the rolls. The filler conveniently may be formed of a shell 131 of boiler plate lined with a sheet 133 of lead or other conductive material insolu ble in the electrolyte. For making the filler formretaining, it is herein provided with conveniently spaced internal wooden partitions 135, the peripheries of which conform to the inner surface of the shell, while extending lengthwise of the filler are shown channel beams 137 to which the several partitions are secured.

For securing a satisfactory flow of electrolyte, each trough of the fillers may, if desired, be provided with inlet and outlet control dams 39 and 49 similar to the inlet and outlet control dams 39 and 49 of the main trough, the inlet and control dams of the filler troughs providing arcuate orifices 41 and 51 similar to the arcuate openings 41 and 51 of the main trough.

The filler shown by Fig. 8 is similar in all respects to the filler shown in Fig. '7, except that it provides four parallel troughs 139 for four rolls 141.

In using the fillers, it will be observed that in the present embodiment of the invention the shells of said fillers are in electrical contact with the shell of the main trough, so that the fillers when in use will constittue insoluble anodes cooperating with the cathode surfaces afforded by the rolls.

For supporting the drums 129 and 141, suitable channel beams 143 and 147, similar to the channel beams 61, may be provided. As shown, the channel beams 143 and 147 support bearings 149 Y on said shafts.

for the shafts 151 of the smaller drums, and further support straps 153, the latter similar to the straps 103 hereinbefore described, for connecting the negative terminal of a source of electro-- motive source to the removable collector rings 155 For driving the smaller drums, one of the drums may be driven by driving means similar to that hereinbefore described and the remaining drums be belted to that drum, as will readily be understood by those skilled in the art.

As an example of the use of the apparatus herein described, but without limitation thereto, satisfactory results have been secured when plating iron print rolls 2 feet in diameter and 5 feet long with copper inch thick by rotating said drums at R. P. M. and passing 500 gallons.

were submerged through an arc of about 130 degrees, and the electrolyte was a copper sulphate solution containing about 10 ounces of sulphuric acid and 9 ounces of copper per gallon, whilethe current density was about 250 amperes per,

square foot of cathode surface.

It will be understood that the embodiment of the invention herein described is merely illustrative of the invention and that wide deviations from the same may be made without departing from the spirit of the invention.

I claim '1. Electrolytic apparatus for depositing metal from an electrolyte upon a cylindrical cathode surface, comprising a trough of insoluble anode material for the electrolyte, the inner surface of that portion of said trough which receives the electrolyte conforming to the surface of a cylinder, and a filler for said trough adapted to be removably received therein, said filler formed to provide a trough of insoluble anode material of smaller radius than said first mentioned trough for cooperation with other cylindrical cathode surfaces.

2. A plating cell comprising a trough of conductive material for the electrolyte, and a filler member having a trough of smaller cross-sectional area adapted to be removably received within said first mentioned trough, said filler member constituting an electrode adapted to cooperate with a cylindrical cathode and exteriorly thereof fitting the walls of said first mentioned trough in electrical contact therewith.

3. A plating cell comprising a trough for the electrolyte, the Walls of said trough constituting an electrode adapted to cooperate with a cylindrical cathode, and a filler member having a trough of smaller cross-sectional area adapted to be removably received within said first mentioned trough, the walls of said trough of said filler member constituting an electrode adapted to cooperate with a cylindrical cathode of smaller diameter than the first mentioned cylindrical cathode, said filler member exteriorly thereof fitting the walls of said first mentioned trough in electrical contact therewith.

4. A plating cell comprising a trough of electrically conductive material for the electrolyte, and a filler member of electrically conductive material having a trough of smaller cross-sectional area adapted to be removably received within said first mentioned trough, said filler member exteriorly thereof fitting the walls of said first mentioned trough in electrical contact therewith.

5. An electrolytic cell comprising a trough-like anode, and a member having a. trough-like anode of smaller cross-sectional area adapted to fit within said first trough in electrical contact with the walls of the latter.

6. Electrolytic apparatus comprising a container for the electrolyte, and a plurality of removable filler members for said container adapted to fit the walls thereof, said filler members having troughs for the electrolyte of different cross-sectional areas.

'7. Electrolytic apparatus comprising a container for the electrolyte providing a trough of conductive material the inner walls of which conform to the surface of a cylinderadapting it to cooperate with a cylindrical cathode, and a filler for said trough having a surface of conductive material adapted to fit the walls of said trough, the upper side of said filler formed of conductive material to present a trough of similar shape to the first mentioned trough but of smaller cross-section adapting it to cooperate with a cylindrical cathode of smaller diameter than the first mentioned cylindrical cathode.

8. Electrolytic apparatus comprising. a container for the electrolyte providing a trough of conductive material the inner walls of which conform to the surface of a cylinder, a filler for said trough having a surface of conductive material adapted to fit the walls of said trough, the upper side of said filler formed of conductive material to present a trough of similar shape to the first mentioned trough but of smaller cross-section, and means for rotatably supporting drums of different diameter to be plated coaxially of both of said troughs.

9. Electrolytic apparatus comprisng a container for the electrolyte providing a trough of conductive material the inner walls of which conform to the surface of a cylinder, means for flowing electrolyte through said trough lengthwise thereof, a filler for said trough having a surface of conductive material adapted to fit the Walls of said trough, the upper side of said filler formed of conductive material to present a trough of similar shape to the first mentioned trough but of smallercross-section, said filler adapted to interrupt the flow of electrolyte through said first mentioned trough except by way of the trough of said filler.

10. Electrolytic apparatus comprising a container for the electrolyte providing a trough of conductive material the inner walls of'which conform to the surface of a cylinder, means for supplying electrolyte to said first ,mentioned trough at one end portion thereof and for discharging it from the opposite end portion thereof, a filler for said trough of shorter length than the latter having a surface of conductive material adapted to fit the walls of said trough, the upper side of said filler formed of conductive material to present a trough of similar shape to the first mentioned trough but of small cross-section, means for supplying said filler adapted to interrupt the flow of electrolyte through said first mentioned trough except by way of the trough of said filler.

11. Electrolytic apparatus comprising a trough having at one end portion thereof an inlet for electrolyte and at the opposite end portion thereof a weir for the electrolyte, and a filler for said trough adapted to fit the walls thereof between said end portions, said filler having at its upper side a trough of smaller cross-section than said first mentioned trough.

12. Electrolytic apparatus having, in combination, an elongated trough the inner surface of which is formed of sheet lead curved to conform to the surface of a cylinder, removable means for rotatably supporting coaxially of said trough a drum to be plated, a removable filler member adapted to be placed in said first mentioned trough, said filler member having a lower outer surface formed of sheet lead conforming to said inner surface of said trough, the upper surface of said filler member formed of sheet lead to pro vide a trough conforming to the surface of a cylinder of smaller diameter than said first mentioned cylinder, and removable means for rotatably supporting a drum to be plated coaxially of said last mentioned trough.

l3. Electrolytic apparatus comprising, in combination, a trough formed of sheet iron bent to conform to the surface of a cylinder, a sheet of lead covering the inner side of said trough, spaced trough supporting members having upper surfaces conforming to the-under side of said trough, and supports for rotatable drums to be plated carried by said supporting members.

14. Electrolytic apparatus comprising, in combination, a trough the inner surface of which conforms to the surface of a cylinder for guiding the electrolyte in contact with a cylindrical cathode surface in close proximity to said inner surface, orifice means at one end of said trough adjacent said inner surface thereof adapted to distribute the electrolyte over said inner surface and direct the electrolyte in the form of an arcuate sheet into the space between said surface and the opposed surface of said cathode, and means for delivering electrolyte to said orifice means.

15. Electrolytic apparatus comprising, in combination, a trough the inner surface of which conforms to the surface of a cylinder for guiding the electrolyte in contact with a cylindrical cathode surface in close proximity to said inner surface, a dam at one end portion of said trough slightly spaced from the walls thereof, and means for delivering electrolyte to said trough behind said dam for delivery through such space to the body of said trough.

16. Electrolytic apparatus comprising, in combination, a trough the inner surface of which conforms to the surface of a cylinder for guiding the electrolyte in contact with a cylindrical cathode surface in close proximity to said inner surface, and inlet and outlet orifices for said trough comprising substantially arcuate orifices close to said inner surface in alignment with the space between said surface and the opposed surface of said cathode.

l7. Electrolytic apparatus comprising, in combination, a trough the inner surface of which conforms to the surface of a cylinder for guiding the electrolyte in contact with a cylindrical cathode surface in close proximity to said inner surface, means for delivering electrolyte to one end of said trough and distributing it in a substantially arcuate sheet in close proximity to said inner surface and directing said sheet into the space between said surface and the opposed surface of said cathode, and means for discharging electrolyte from the opposite end of said trough comprising substantially a submerged orifice extending transversely of said trough in close proximity to the walls thereof.

18. Electrolytic apparatus comprising, in combination, a trough the inner surface of which conforms to the surface of a cylinder for guiding the electrolyte in contact with a cylindrical cathode surface in close proximity tosaid inner surface, means for maintaining a body of flowing electrolyte at constant level in said trough comprising overflow and underflow weir means at the discharge end of said trough, and means at the opposite end of said trough for delivering electrolyte thereto and distributing it in a substantially arcuate sheet in close proximity to said inner surface and directing said sheet into the space between said surface and the opposed surface of said cathode.

19. Electrolytic apparatus comprising, in combination, a trough the inner surface of which conforms to the surface of a cylinder for guiding the electrolyte in contact with a cylindrical cathode surface in close proximity to said inner surface, and inlet and outlet means for the electrolyte comprising substantially submerged arcuate orifices close to said inner surface for causing the electrolyte to be directed in the form of an arcuate sheet through the space, between said inner surface and the opposed surface of said cathode.

20. Electrolytic apparatus comprising, in combination, a trough the inner surface of which conforms to the surface of a cylinder for guiding the electrolyte in contact with a cylindrical cathode surface in close proximity to said inner surface, and inlet and outlet means for the electrolyte comprising dams at opposite ends of said trough,

the edges of said dams slightly spaced from said inner surface.

21. Electrolytic apparatus comprising, in combination, a trough the inner surface of which conforms to the surface of a cylinder for guiding the electrolyte in contact with a cylindrical cathode surface in close proximity to said inner surface, means at one end of said trough comprising a dam slightly spaced from said inner walls, and.

means for flowing electrolyte downwardly in said trough behind said dam for delivery to the body of said trough through such space.

22. Electrolytic apparatus comprising, in combination, a trough the inner surface of which conforms to the surface of a cylinder for guiding the electrolyte in contact with a cylindrical cathode surface in close proximity to said inner surface, a pair of spaced dams at one end of said trough, one of said dams communicating with the body of said trough through orifice means close to said inner surface adapted to distribute the electrolyte over the latter, and means for delivering electrolyte behind the other dam and causing it to flow over it for delivery to said orifice means.

23. Electrolytic apparatus comprising, in combination, a trough the inner surface of which conforms to the surface of a cylinder for guiding the electrolyte in contact with a cylindrical cathode surface in close proximity to said inner surface, a pair of spaced dams at one end of said trough, one of said dams having a downward inclined breast for delivering electrolyte downwardly toward the other of said dams, the latter communicating with the body of said trough through submerged orifice means close to said inner surface adapted to distribute the electrolyte over the latter.

24. Electrolytic apparatus comprising, in combination, a trough the inner surface of which conforms to the surface of a cylinder for guiding the electrolyte in contact with a cylindrical cathode surface in close proximity to said inner surface, a pair of spaced dams at one end of .said trough, one of said dams having a downward inclined breast for delivering electrolyte downwardly toward the other of said dams, the latter communicating with the body of said trough through subbmerged orifice means close to said inner surface adapted to distribute the electrolyte over the latter, and a splash plate between said dams.

25. Electrolytic apparatus comprising, in combination, a trough the inner surface of which conforms to the surface of a. cylinder for guiding the electrolyte in contact with a cylindrical cathode surface in close proximity to said inner surface, a pair of spaced dams at one end of said trough, one of said dams having a downward inclined breast for delivering electrolyte downwardlytoward the other of said dams, the latter communicating with the body of said trough through submerged orifice means close to said inner surface adapted to distribute the electrolyte over the latter, and means providing a transversely extending edge in spaced relation to said inclined breast adapted to contact with the surface portion of said electrolyte.

26. Electrolytic apparatus comprising, in combination, a trough the inner surface of which conforms to the surface of a cylinder for guiding the electrolyte in contact with a cylindrical cathode surface in close proximity to said inner surface, a dam having an incline breast at one end of said trough, and means providing a transversely extending edge in spaced relation to said breast adapted to contact with the surface portion of said electrolyte.

2'7. A plating cell comprising a trough-shaped electrode for containing the electrolyte and adapted to coact with a cylindrical cathode, and a member having a trough-shaped electrode of smaller cross-sectional area for containing the electrolyte adapted to be removably received within said first mentioned trough and to coact with a cylindrical cathode of smaller diameter than the first mentioned cylindrical cathode, said member coacting with the walls of said trough which receive it to prevent contact of the electrolyte therewith at the portions thereof where said member is situated.

28. A plating cell comprising a trough of conductive material, an inlet for electrolyte at one end of said trough and a discharge for the same at the opposite end thereof, a filler member having a trough of conductive material adapted to constitute an anode for a cylindrical cathode, said filler member adaptedto be received within said first mentioned trough between the inlet and outlet thereof in electrical contact therewith and to prevent communication between said inlet and outlet except by way of said trough of saidfiller member.

29. Plating cell apparatus comprising a trough, means constituting an inlet for electrolyte at one end of said trough and a discharge for the same at the opposite end thereof, a plurality of removable flller members each having a trough of conductive material conforming to the surface of a cylinder, the trough of each filler member having a different radius'of curvature as compared with the'troughs of the other filler members, and each filler member adapted to be inserted in said first mentioned trough with one end of the trough of the filler member adjacent said inlet and the opposite end thereof adjacent said outlet, each filler member being adapted to interrupt communication between said inlet and outlet except by way of the trough of the filler member longitudinally thereof. I

30. Plating cell apparatus comprising a trough of conductive material, means constituting an inlet for electrolyte at one end of said trough and a discharge for the same at the opposite end thereof, a plurality of filler members each having a trough of conductive material conforming to the surface of a cylinder, the trough of each filler member having a different radius of curvafiller members, and each filler member adapted to be inserted in said first mentioned trough in electrical contact with the walls thereof between the inlet and outlet thereof and to interrupt communication between said inlet and outlet except by way of the trough of the filler member.

RICHARD A. WILKINS.

CERTIFICATE OF comcriou,

Patent Neo 1, 978, 356.;

om gs, i934,

RICHARD A. WILKINS.

It is hereby certified that error appears in the printed specification ofthe above numbered patent requiring 8, fcr"diametcr" read "diameters"; words "means for supplying"; and inclined; and that the (deal) correction as follows:

Page 3, line 108, claim and lines 136-137, claim 10, strike out the page 5, line 25, claim 26, for "incline" me said Letters Patent should be therein that the same may-conform to the record of Signed and sealed this 12th day of February,

read with these corrections bcsiie Frazer Afifi unit 9% the case in the Patent Office.

110 ture as compared with the troughs of the other inner surface adapted to distribute the electrolyte over the latter, and a splash plate between said dams.

25. Electrolytic apparatus comprising, in combination, a trough the inner surface of which conforms to the surface of a. cylinder for guiding the electrolyte in contact with a cylindrical cathode surface in close proximity to said inner surface, a pair of spaced dams at one end of said trough, one of said dams having a downward inclined breast for delivering electrolyte downwardlytoward the other of said dams, the latter communicating with the body of said trough through submerged orifice means close to said inner surface adapted to distribute the electrolyte over the latter, and means providing a transversely extending edge in spaced relation to said inclined breast adapted to contact with the surface portion of said electrolyte.

26. Electrolytic apparatus comprising, in combination, a trough the inner surface of which conforms to the surface of a cylinder for guiding the electrolyte in contact with a cylindrical cathode surface in close proximity to said inner surface, a dam having an incline breast at one end of said trough, and means providing a transversely extending edge in spaced relation to said breast adapted to contact with the surface portion of said electrolyte.

2'7. A plating cell comprising a trough-shaped electrode for containing the electrolyte and adapted to coact with a cylindrical cathode, and a member having a trough-shaped electrode of smaller cross-sectional area for containing the electrolyte adapted to be removably received within said first mentioned trough and to coact with a cylindrical cathode of smaller diameter than the first mentioned cylindrical cathode, said member coacting with the walls of said trough which receive it to prevent contact of the electrolyte therewith at the portions thereof where said member is situated.

28. A plating cell comprising a trough of conductive material, an inlet for electrolyte at one end of said trough and a discharge for the same at the opposite end thereof, a filler member having a trough of conductive material adapted to constitute an anode for a cylindrical cathode, said filler member adaptedto be received within said first mentioned trough between the inlet and outlet thereof in electrical contact therewith and to prevent communication between said inlet and outlet except by way of said trough of saidfiller member.

29. Plating cell apparatus comprising a trough, means constituting an inlet for electrolyte at one end of said trough and a discharge for the same at the opposite end thereof, a plurality of removable flller members each having a trough of conductive material conforming to the surface of a cylinder, the trough of each filler member having a different radius'of curvature as compared with the'troughs of the other filler members, and each filler member adapted to be inserted in said first mentioned trough with one end of the trough of the filler member adjacent said inlet and the opposite end thereof adjacent said outlet, each filler member being adapted to interrupt communication between said inlet and outlet except by way of the trough of the filler member longitudinally thereof. I

30. Plating cell apparatus comprising a trough of conductive material, means constituting an inlet for electrolyte at one end of said trough and a discharge for the same at the opposite end thereof, a plurality of filler members each having a trough of conductive material conforming to the surface of a cylinder, the trough of each filler member having a different radius of curvafiller members, and each filler member adapted to be inserted in said first mentioned trough in electrical contact with the walls thereof between the inlet and outlet thereof and to interrupt communication between said inlet and outlet except by way of the trough of the filler member.

RICHARD A. WILKINS.

CERTIFICATE OF comcriou,

Patent Neo 1, 978, 356.;

om gs, i934,

RICHARD A. WILKINS.

It is hereby certified that error appears in the printed specification ofthe above numbered patent requiring 8, fcr"diametcr" read "diameters"; words "means for supplying"; and inclined; and that the (deal) correction as follows:

Page 3, line 108, claim and lines 136-137, claim 10, strike out the page 5, line 25, claim 26, for "incline" me said Letters Patent should be therein that the same may-conform to the record of Signed and sealed this 12th day of February,

read with these corrections bcsiie Frazer Afifi unit 9% the case in the Patent Office.

110 ture as compared with the troughs of the other 

